A traditional advantage of low density polyethylene (LDPE) over linear low density polyethylene (LLDPE) in extrusion processes such as cast film and extrusion coating is a lower level of neck-in during processing. “Neck-in” refers to the tendency of the film to draw in at the edges of a flat die. A lower level of neck-in may permit the production of a wider film or coating with the same die size. In addition, the neck-in may thicken the film at the edge of the extruded film or coating resulting in a higher level of waste material that must be trimmed.
However, LDPE may be limited in gauge to which it can be drawn. Traditionally, at lower gauges, the LDPE film tears and thinner film or coatings in certain situations cannot be produced. LLDPE typically has a greater capability to be drawn to thinner films and coatings. With respect to the final film or coating properties, some properties are improved by LLDPE and others by LDPE.